Wedding etiquette isn't the same as it was 20 years ago, and neither are the weddings themselves. From living together before you're married to wearing a color other than white and registering for a honeymoon instead of new plates, a lot has changed. However, there are some things that will always stay the same. Here are 18 wedding etiquette rules for couples and guests that aren’t going anywhere.

Be gracious

More than just saying "please" and "thank you," being gracious is a state of mind that you should carry throughout your wedding day. Be kind and pleasant as you work with your vendors or deal with your wedding party, be warm and welcoming as your guests arrive, and be polite and courteous. It may be your big day, but by acknowledging and appreciating what others have done to make it happen, you'll stick in their minds as a bride for the books, not a bridezilla for the gossip mill.

Don’t invite a guest to a pre-wedding party if they aren’t invited to the wedding

One of the easiest ways to upset a friend or relative is to host them at a bridal shower or bachelor party, then not invite them to the wedding. Reserve the guest lists for events including engagement parties, showers, and bachelorettes for guests of the wedding only.

Send a paper invitation

In a world full of digital messages like email and social media, your wedding is the moment to mail a formal, paper invitation. How beautiful, right? Keep it simple with a printed invitation or go elaborate with a full stationery suite—whatever you choose, follow the proper etiquette for addressing your guests on the envelopes. Click here for a complete guide on how to address wedding invitations.

Don’t include registry information on your invitations

It’s best to avoid placing registry information on your paper invitation. Instead, include your registry on your wedding website, and share your website address on the stationery. Registry links on your invitation are considered distasteful, as you don’t want to look like you’re soliciting gifts. Plus, the website typically includes additional helpful information for your guests, like travel tips and accommodation details, making it the more logical location anyway.

Thank your wedding party

Let your friends and family in your wedding party know how much you love the support they have given you as your bridesmaids and groomsmen. Do something special for each person, whether it’s a fancy gift, a handmade present, or a special note. They will appreciate that you recognized the time and effort they put in to making your wedding day a success.

Avoid a cash bar

We know that the food and beverage tally adds up quickly, but that’s no excuse for charging your guests. Refrain from asking friends and family to pay for their drinks. Instead, find other ways to save. Cut back in another category or pare down the full bar to offer a few select options. Consider providing beer and wine only. It’s a great way to save, and guests likely won’t miss the hard liquor.

Consider your guests’ comfort and have an inclement weather plan

Whether it’s what to do in the event of rain, extreme heat, or freezing cold, have a plan B that you love in case you must enact it. You may want an outdoor ceremony and be ok with raindrops, but your 200 guests probably won’t like huddling under umbrellas to watch you say “I do.” Think about what will keep them comfort: provide shawls or fans depending on the temperatures, and move the party indoors if that everyone will be more focused on the weather than your vows.

Send thank you notes to your vendors

Yes, you’ve paid for their services, but vendors love hearing how much you appreciate their time and effort to pull off your special day. Send a handwritten thank you note to everyone on your vendor team. If you wish, include gratuity for their hard work.

Send thank you notes to your guests

Show your guests your appreciate their presence, support, and gifts by sending them a handwritten thank you note from you and your new spouse. Tell them how much it means to you that they witnessed you say your vows and celebrate on the dance floor. If you received a gift from that guest, mention the specific item in the note. Your guests will be very impressed with your thoughtfulness.

Celebrate within your means

Money is a touchy subject, and it can become emotionally charged when it comes to your wedding. Whether you are paying for your celebration yourself or have received a gift from a family member to cover the costs, be acutely aware of how much you have to spend—and don't go beyond that amount. There is no need to go into debt for your wedding. Your celebration will be special and beautiful no matter what you're paying for it.

As a guest, don’t wear white

Unless the couple specified a white party as the dress code, steer clear of white, ivory, and cream tones. That goes even if the brides chooses to wear a different hue, like pastel pink or blue. If you’re attending a wedding with two grooms, it’s still best to err on the conservative side: avoid the color or ask the couple their preference. You never know if they will choose to don white themselves.

Do get the couple a card or a gift

Let the newlyweds know how honored you are to celebrate with them. Even the smallest gift or the simplest greeting card shows you care. Sign a card with your congratulations, and if there is a registry, considering purchasing the couple a gift. Most couples include items of varying price points, so you can find something that fits your budget.

Don’t bring a plus one if you weren’t invited with one

If your invitation does not read “and guest” or list your guest's name, it’s an invitation for you to arrive solo. Use this as a chance to get to know new people in the couple’s circle rather than bothering the couple to make an exception so you can bring a date.

Don’t bring children if the invitation says “no children”

Similarly, don’t ask the couple if you can bring your kids. Respect the couple’s wishes if they want an adults-only celebration. Instead, consider your childcare options at home or at the destination. It is okay to inquire with the couple about local babysitters, especially if you are from out of town. Many couples will have this information to pass along to guests with little ones.

Be respectful in houses of worship

If the couple plans to say “I do” in a church, synagogue, temple, or other religious institution, consider the appropriate decorum and attire for such a venue. Ladies should consider covering their shoulders for the ceremony with a jacket or wrap, and men should remove hats unless they are traditional, such as a turban or yarmulke.

Put down your phone for an unplugged ceremony

If the couple requests that you shut off your phone, don’t pull it out to take pictures of the first kiss. Leave the photography to the pros—the couple paid good money for them!—and be present in the moment. There’s a good chance you can snap away at the reception, so save the selfies for the dance floor.

Observe the couple’s wishes

Remember, it’s their day not yours. You’re there to celebrate the newlyweds, witness their vows, and take part in the festivities. Try to put their needs before your own, and avoid complaints about the food or a detail you didn’t like. Save the comments for another day and instead, be positive. No one likes a grouchy guest.